Full dimensional ab initio direct dynamics calculations of the ionization of H2 clusters (H2)n (n= 3, 4 and 6)
Full dimensional ab initio direct dynamics calculations of the ionization of H2 clusters (H2)n (n= 3, 4 and 6)
复制标题
H2 团簇 (H2)n (n= 3、4 和 6) 电离的全维从头算直接动力学计算
DOI：
10.1039/b004969g
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发表时间：
2000
影响因子：
3.3
通讯作者：
H. Tachikawa
中科院分区：
文献类型：
--
作者：
H. Tachikawa
的
（H2+）（H2）n−1团簇在（H2）n（n）离子化后的dyridges
= 3，4和6），这起着重要的
在电子束辐照固体氢的初始过程中的作用，已被研究，
从头算直接动力学计算的手段。全维势能面（PES）计算
在整个过程中使用了UHF/311 G（p）级。星系团中的一个氢分子
在时间零点电离计算表明，H2分子逐渐接近电离氢
在反应的初始阶段，氢分子与H2+碰撞，然后其中一个氢分子与H2+碰撞（接近时间约为100 fs）。氢原子或质子转移反应迅速发生，
H2+与H2的碰撞，根据反应H2+
+ H2
→ H3+
+ H（反应时间约为10 fs）。氢
原子以大的平移能离开团簇（7-26 kcal mol−1，取决于团簇的大小）。
子离子H3+是振动和旋转热的。在某些情况下，H3+被溶剂化
相邻H2
形成离子-分子簇（H3+）（H2）m（m
= 1-3）。相似的动力学特征
获得了每个聚类（n
= 3、4和6）。在理论分析的基础上，对反应机理进行了探讨
结果值得注意的是，本研究
是第一
试图阐明
氢原子团簇的电离动力学
The
dyamics of (H2+)(H2)n−1 clusters following the ionization of (H2)n (n
= 3, 4 and 6), which plays an important
role in the initial processes of electron-beam irradiation of solid hydrogen, have been investigated by
means of ab initio direct dynamics calculations. The full dimensional potential energy surface (PES) calculated
at the UHF/311G(p) level was used throughout. One of the hydrogen molecules in the cluster was vertically
ionized at time zero. The calculations showed that the H2 molecules gradually approach the ionized hydrogen
molecule H2+ in the initial stage of the reaction and then one of the hydrogen molecules collides with H2+ (the approach time is about 100 fs). The hydrogen atom or proton transfer reaction occurs rapidly by
collision of H2+ with H2, according to the reaction H2+
+ H2
→ H3+
+ H (the reaction time is about 10 fs). The hydrogen
atom leaves the cluster with large translational energy (7–26 kcal mol−1, depending on the cluster size).
The product ion H3+ is vibrationally and rotationally hot. It was also found in some cases that H3+ is solvated
by neighboring H2
molecules to form the ion–molecule cluster (H3+)(H2)m (m
= 1–3). Similar dynamics features
were obtained for each cluster (n
= 3, 4 and 6). The mechanism of the reaction is discussed on the basis of the theoretical
results. Note that the present study
is the first
attempt to elucidate
the ionization dynamics of hydrogen clusters.